1. Field of the Invention
The present invention relates to an information recording and reproducing apparatus for guiding and conveying a film to which a magnetic or optical recording portion is provided by a conveying guide and for recording or reading information on or from the magnetic or optical recording portion by a reading/recording means corresponding to the magnetic or optical recording portion.
2. Description of the Related Art
In recent years, a system has been called for in which a magnetic recording portion (i.e., a recording track) is provided in a photographic film. Necessary or effective information, e.g., a photographing date, a title, the number of prints, and print size, is recorded on the magnetic recording portion at the time the camera is photographing or at the time the film is accepted at a so-called photo processing shop for processing. The recorded information is effectively used at the time of printing in a film processing laboratory.
With this system, as illustrated in FIG. 8, a magnetic head 100 is mounted to a piece of laboratory equipment with in a film processing laboratory. Magnetic information recorded on a recording track 104 which is located outside a screen of a film 102 (i.e., outside an image frame) is read by causing the magnetic head 100 to slide on the recording track 104 when the film 102 is conveyed.
On the other hand, in a transport apparatus for conveying the film 102, a conveying guide 106 is used which guides both end portions of the film 102 in a transverse direction thereof. The distance between both ends of the conveying guide 106 in a transverse direction thereof is made a little greater than the transverse dimension of the film 102, thereby improving the passing property of the film 102.
In this case, this dimensional difference between the film 102 and the conveying guide 106 causes the film 102 to move in a zigzag direction when the film 102 is conveyed. It should be noted that the zigzag movement of the film 102 has no influence upon the detection of notches, an ordinary printing processing, or the like.
However, since the strength of a read signal becomes small (i.e., the read signal deteriorates) by a slight change of the relative positional relationship between the magnetic head 100 and the recording track 104, it is necessary to provide means for preventing the relative positional relationship between the magnetic head 100 and the recording track 104 from changing even if the film 102 moves in the zigzag direction.
Accordingly, a magnetic head following system has been conventionally used so as to minimize deterioration of the read signal. This magnetic head following system is constructed such that a guide plate 108 to which the magnetic head 100 is fixed is provided in a cut-off portion of the conveying guide 106 in such a manner that the guide plate 108 can move close to and apart from the film 102, and the guide plate 108 is urged against a side edge of the film 102 by an urging force of an urging means 110.
Since the guide plate 108 follows the film 102 moving in the zigzag direction by means of the urging force of the urging means 110, the relative positional relationship between the magnetic head 100 and the recording track 104 can be kept substantially in a fixed state.
However, in the above-described magnetic head following system, the guide plate 108 is constantly urged against the side edge of the film 102. For this reason, when large stepped or concave portions (for example, a notch 102A, a joint portion 114 using a splicing tape 112, and the like) are formed on the side edge of the film 102, the guide plate 108 may move along these stepped portions (see FIG. 9).
Since the film 102 is conveyed at a high speed, when the guide plate 108 suddenly falls into the notch 102A or the guide plate 108 comes out from the notch 102A, the magnetic head deviates largely from the recording track 104. As a result, the magnetic information cannot be correctly read. Further, when the stepped portions which narrow largely in the transverse direction of the film 102 is formed, the film 102 itself may be damaged.
Further, the transverse dimension of the film may be reduced in the joint portion 114. Accordingly, deviation of the magnetic head 100 and the guide plate 108 becomes even larger.